Its not a good idea to wear a skirt while bowling, unless you wanna give a free show and be majorly uncomfortable.
dont wear the skirt. if ur bowling...silly. theyll not only think somethings up. but also that's indecent exposure...not everyone wants to see that. or at least I'm sure he doesn't want them to. besides why are you sneaking behind your parents backs. a mature girl would tell her parents that she's dating an older guy who sounds like a perv to me. anyway. when I went bowling with my ex. she just wore tight jeans. as to show off the butt. but leave it to the imagination. just wear a cute top to go with.
I say just wear the skirt. They won't suspect anything.
WHY WOULD THEY THINK SOMETHING IS UP IF YOU WEAR A SKIRT?