You can either do this .
Become the most funniest and interesting person in the conversation ( its hard)
or undermine everything the guy says in a nice way
Guy " so yeah ive got this red sports car "
you " Wow thats amazing , what engine ? how fast etc . ( you seem interested ) and then you would say something like " well you know what they say about guys with sports cars

" ( small dicks ) etc
do this with whatever theyre wearing as well . " Wow I love your fashion sense , where did you buy that from ?"
guy : answer
you : Oh im surprised i thought it would have been a camp shop , but it works well
and if you realy want to be an ass " maybe next time you could buy that top in a mans size "
Your complimenting him and undermining him if you get me .