Is it okay for a guy that just ask a girl out after a week..

Sophia
So me and my co worker goes to the same school. We're not close at school in fact we never even talk at school but at work we're really close. We're so close to the point that it is more obvious than friendship but he always has a gf and I never want to interrupt their relationship. Usually he would tell me about all their problems and would complain to me all the time how he wishes he could be with me which I find it very strangth. Then a month ago he told me he has a crush on me and try to kiss me but I pushed him away because I couldn't accept the fact that he's still has a gf. I do like him a lot but I have enough moral. Then a weel ago which a day before Valentine he broke up with his gf and surprise me with a flower, instead of happy I was so upset and got very mad at him for did that to a girl. Today he asked me out! I don't know what to say.. Because it's too quick for me. And a bunch of people at school are not happy for what he did to his gf cuz they're both very popular and everyone know them. If I go out with him it would just be weird cuz we don't even usually talk and not from the same group I guess.