I thought about that after I posted. What I meant was that something light, entertaining and a "step back" from what he's capable of might make it more enjoyable. I'm pretty sure you don't want him reading smutty French books, right? I bet there are some cool French graphic novels or something. My youngest sister read a lot of TinTin in French.
Gaye joining the chorus of not inviting that kind of stress. A park or coffee shop or other situation where there's less pressure on you and on your son will probably make the whole situation easier. Even meeting them without your son for the first time might be wise. (In a strange reverse situation, my kids met my FIL's new girlfriend over the summer, and it was pretty confusing for my oldest at seven. She wasn't sure how much of a "grandma" she might be, and as a woman who doesn't have any kids it's not a natural role for her. All is good, but we really downplayed the relationship to keep it low pressure. Yes, she's his girlfriend, but she's not your grandparent..)
JayGee, sending lots of healing to your dad.
RR- Bootcamp tonight
NRR- Insert grumble about my partner's stress level here.