Welcome to HCM
We understand your concerns
You have been sexually active for 10 years and still you are. You are just 27 and has at least another 30 years of sexual life. So just don't get disappointed in such silly happenings. If you become disappointed in such silly happenings, you might become anxious and lose your future sexual life.
Testicles are supposed to be tight when we have intercourse or masturbation
or excited. Normal relaxed position is a bit loose.
Don't be anxious and enjoy sex.