Event One ( FRIendship )

as stated before, Vreth found Gale while he was stuck in the portal on the rock. Though they had an awkward beginning, they became good friends quickly due to each others love for talking about anything and everything. They instantly became permanent traveling buddies. It just felt wrong when they weren't together. They often talked while Gale cooked and showed each other magic. Though Vreth never really cared about reading, he would try and read whatever Gale suggested to him. They find each other so intrigued with each other, which they haven't realized yet is caused by their feelings for each other.
During the Tiefling party, Vreth socialized for a bit, but he eventually went to hang out with Gale, and stayed there for the rest of the night. Talking to Gale made him feel like they were the only two people in the word, as if there wasn't a party going on around them. That night was the night they did the night of magic, where feelings were half-admitted, but they both blamed it on the alcohol and tried really hard to pretend it never happened.
Neither of them were good with hiding their emotions, but both tried to deny the signs and tried to make excuses as to why these signs were actually happening. Neither of them wanted to believe that the other TRULY had feelings, but something within them begged with everything that it was truly what was happening...
Once Gale had the conversation with Elminster about Mystras order for  him to kill himself using the orb, Vreth spends a lot more time with  Gale, trying to comfort him as much as possible. Vreth tries to keep a  close eye on him, due to Gales sudden suicidal thoughts and the  influence Mystra has on him from grooming him for years.

Event Two ( relationship )

As usual, Gale confessed his feelings during the night with the stars. A bit hard for both of them, because they both wish that they can take things slow. With the threat of The Absolute, that's nearly impossible, no matter how bad they want it. Though Vreth lets Gale show him the vision of Waterdeep, they don't astral project. They ended up staying out in the field for the rest of the night, away from everyone, where they could truly be alone together for once.
Vreth and Gale become nearly insepperable after that, especially at camp. For a moment, they were both too scared and awkward to show any sort of affection, but once they're comfortable they're never seen without each other. They discuss just about everything that happens during their travels together. Due to them both feeling like outcasts, they found comfort and bond in each other.
After Gale sees the crown of Karsus and gains an interest in it, Vreth becomes extremely concerned with him. Vreth doesn't like his interest in the crown at all, and he could see exactly why he wanted it. Vreth tried to assure Gale at any given moment that he loved him the way he was, he didn't need to make any grand gestures, he didn't need to prove himself, and he definitely doesn't need to become a god. He felt like nothing he did or said did anything to help.
When they finally found the Book of Karsus, Vreth really didn't want to give it to Gale at first, and tried refusing it at first. When Gale got upset with him and demanded the book, Vreth eventually gave it to him, as much as he didn't want to. Vreth pleaded with him to drop it as much as he could. He was so scared he was going to lose the one he loved.
During the boat scene, where Gale talks about becoming a god with the Karsus crown, Vreth again tries to tell him that he loves him the way he is. Gale can't understand why Vreth loves him the way he is, and Vreth can't understand why Gale would lose everything to become a god. They both become frustrated that the other can't see their perspective. Though frustrated, they always hear each other out, like they always do, and Vreth continues to voice his discomfort.
When Gale wants to see Mystra, Vreth originally tries to convince him not to, but eventually agress to let him see her. Once they find out that if they give the crown to Mystra it'll get rid of Gales orb permanently, Vreth is determined to defeat the absolute and give the crown to her so he can save Gale. Though Gale hesitated, he eventually agreed.

Event Three ( Post - Game )

Vreth and Gale succeeded in defeating the absolute and getting rid of Gales orb. After everything, Gale asks Vreth to come back to Waterdeep with him and marry him, which Vreth of course agreed. Once they got back to Waterdeep, it took them awhile to become officially wed, but they considered themselves married anyways. They wanted to take a long break before doing something so big. For about a year, they mostly stayed in Gales tower, not really communicating with others except for their old camp mates, who they stayed close with even after everything.
During this time of healing, Gale decided to grow his hair a little and go on estrogen for about 4 - 6 months, then stopping eventually. Another bonding time for them, because Vreth is trans and also went through changes in his body.
Though Vreth and Gale never became parents, they eventually adopted a few cats that they consider their children.