I don't know where you are departing from but that is an awful lot of travel in a very short period of time. Arriving late Wednesday and leaving early Monday means you effectively only have 4 days in country. To add more travel onto that seems silly to me. You could fly to Phuket but that kills a big part of another day just to get there. And then you don't have all that much time once you get there. And you have to fly back to BKK which adds even more travel.

Why not just stay in BKK. There's a pretty big gay scene, although much of it is commercial. At least the part tourists see anyway. There is a whole other Thai gay scene but it is a little more difficult to access unless you have Thai friends to show you around. And of course there is the communication gap.

You could spend a couple of days seeing the main tourist sights. Do a little shopping. Just taking in the city. Maybe take a day trip to Ayutthaya which is worth a look if you have any interest in history. By the time you do that it will be time to go home.

I just returned from a month in SE Asia. For me going all that way for 4 days is insanity, especially if you spend one of those 4 days doing even more travel.

I think Pattaya is a love it or hate it kind of place. You do see a fair amount of European families there for some reason. It is quite a melting pot. Lots of Russians and Middle Eastern tourists. And plenty of aged (and some not-so-aged) Westerner sex tourists.