Best to drop by LBS yourself and try a different saddle. There's no point trying to convince him otherwise ..when he doesn't have your anatomy. Hopefully you have a receipt for a swap???

A LBS would give the most objective opinion from their perspective..on how often people do come back to try different saddles.

And do some rides yourself on that great bike...you need to build up your endurance, literally and mentally so that you can enjoy rides with him.

I could never be comfortable on my partner's saddle, it's a red hot little Italia..line..narrow profile..