I wholeheartedly believe that Tenna would be so into electroswing if he was ever introduced to it, esp since he already knows the charleston/swing shuffles (the dance he does in the tux). Like, swing was really popular around the time color CRTs were also popular (the 1950s). And since Toriel knows the jitterbug, I wouldn't be surprised if Asgore + Toriel were into that kind of music either. SO OF COURSE TENNA LOVES SWING + DANCING!!!!! Since he wants to connect with the young ppl (how do u do fellow kids? LOL), electroswing hits that sweetspot of his era and the modern. ANYWAY, not me projecting and rationalizing my love for electroswing/swing onto him so he can dance with the reader (or me, really) like this:
It would be so so so cute seeing him let loose and have fun like that w/ the reader (˶˃ᆺ˂˶) Of course, he'll have to shrink down to match their height but!! He'd definitely, instantly, go back to his normal/max height after the dance w/ a flower popping up from his nose, carrying the reader and kissing them silly!!!