Calling all men - why would you do this?

I went on a date with a guy 2 weeks ago, and after a day he texted me that “I was too conceited for him.” I took that with a grain of salt and a laugh considering the source. I didn’t much care being called something I know I am not by someone I barely knew and didn’t really care for after the date. Anyway, immature way on his part to just say “Hey this isn’t going to work out,” but fine. this morning, I get a text him saying “What up conceited”. Seriously? Why, as a man, would you do something like that? Why can’t he just leave it at the first one? BTW I did not respond to either text in case you are wondering. I really just want to know what his motive may be to send the second text.