For what you're looking for, I'd say Bangkok probably, even if I'm not personally a big fan of the city as it's too chaotic for me. Dating might be a bit difficult in Seoul. I just spent 3 months there and love the city so much, the nightlife is a big part of it. But even if you're not a night owl you can have a really good time here as there is so much to do and people are amazing. It's getting super cold right now though.
For what you're looking for, I'd say Bangkok probably, even if I'm not personally a big fan of the city as it's too chaotic for me. Dating might be a bit difficult in Seoul. I just spent 3 months there and love the city so much, the nightlife is a big part of it. But even if you're not a night owl you can have a really good time here as there is so much to do and people are amazing. It's getting super cold right now though.