I remember having that conversation and thankfully it went better than I thought, I was petrified about asking it cause I thought it was going to be a hard no but she said she knew I was gonna ask for it at some point so I think she was mentally ready for it 
Once we spoke about it I got a strap on ordered and just waited for the right time (ie when kids at his nans) to give it a try. Been a regular staple since