How to use a Helix Syn V on my man

I (42 F) bought my boyfriend (46 M) a Helix Syn V for his birthday. He loves prostate play. He’s also talked generally about trying some light fem dom bondage.

He’s tied my up and used toys on me before and it blew my mind.

I’m looking for ideas on how to introduce him to his birthday present. I’d like for him to be blindfolded and at least partially restrained.

What would be a good position to have him restrained in?

Any other suggestions on making this his best birthday ever?