I ride with my wife on the back every once in awhile on the SV - we don't go far, just typically to dinner or something.
We rented a Suzuki Boulevard 650 (thumper) in Maui and did the Road to Hana in shorts and t-shirts and that bike absolutely sucked for two up riding. For a cruiser - what a disappointment. We switched out to a Honda Shadow 750 and it was so...much... better. Again, shorts and t-shirts/tank tops. Rode to the beaches, and went all over the island.
In Bermuda we rented a 50cc 4 stroke scooter
The driving lanes are on the opposite side of the road from us, and the entire island is like 30 minutes from tip-to-tip. That thing was so sketch, and we had half-helmets and shorts and t-shirts/tank tops. And Vans shoes. Carrying picnic and beach stuff. She would read a map propped on my back and give me directions as we putt'ed around
If you got caught stopped on a hill with that scooter, forget it. 0-25MPH in like a minute.
I would like to get a big cruiser for her and I, something at least 750cc's and low and comfy. The SV650 is super cramped and not cool for two up. I wouldn't mind a nice cruiser with a sissy bar and bags for us.
Here's my tip:
Slow the F down. My ego isn't so big I need to go fast with my wife riding passenger. We putt-putt everywhere, on all the two up riding we've ever done. Pull over when necessary. Don't push it when fatigue sets in. Chill. Most of all, relax.
It's a whole different mind set for me. Truly cruising and relaxing. I honestly think people put way too much energy into the safety of it all. Just hold back and set aside the time to get to where you need to go. I have never had a pucker moment, never felt scared or nervous, and she never has either. Even on the islands in zero riding gear. People on BARF put so much energy around safety, I honestly think it creates fear in some people. In over 20 years of riding street, track, dirt, Supermoto, etc., and before that, cruising a 3sp. Honda Passport in my teens, I crashed more during my peak of BARF'ing - professing "safety" on this forum - than just riding relaxed, confident and calm and not being on some sort of safety soapbox.