Relationship with married man...

I was proposed a sexual relationship with a guy who claims to be happily married to his wife. He says he is looking for sex not because he is not happy with his wife just because he feels an attraction to me and wanted to test the water and see if we could get anywhere else.

I will admit he is cute and kinda gets me horny but I get scared of the drama I can’t get into. also he’s only wanting sex and knowing me I might start have feelings for him... I have been ignoring him but he keeps insisting...I know what I should answer but one can fall...😞😫