Burning urination only after sex

this only happens after sex not everytime he goes to the bathroom

my husband has recently complained a few times about a burning sensation when he urinates after we have sex....at first we thought it was from the product i used to cleanse myself..(douch)...but the last time i had not used it for several days prior and yet he still complained of the burning sensation but also said this time that after he went he still felt as if he had to urinate again...so now its starting to concern us...and of course he is kinda reluctant to go to the doctor about it...any suggestions would be helpful

Thanks