HELP!!! - UTI from to much sex or lube?

Mikayla • 17
everytime my boyfriend and i have a lot of sex i end up getting a UTI but when we do have a lot of sex we have to end up using lube ( its a strong flavoured lube ) and when we use the lube it burns during sex.
I also pee after sex to flush out any bad bacteria and lower my risk of a UTI.
Would it be from the sex or the lube?