Claire Q3

Need your help with a sticky situation guys. I have had my new 2017 Q3 a few months and love it. The other day I came out to my car and noticed a crease over my passenger wheel arch. I am 99% my boss opened his passenger rear door into the arch. Funny thing is he drives a BMW 7 series but treats it poorly. I had the dent removed at Audi by PDR but I am worried this will happen again by my boss. What should I say to him in the least awkward way possible? It's assigned parking so moving isn't an option. I was in an hour late Friday from dropping the car off for the PDR and I told him I had to take the car in to have a dent removed from someone opening their door into mine. He just responded with ok. I am really careful with parking and I take care of my things because I work hard to pay for them. I feel like I need to say something more to him to try to make sure he gets it and doesn't fling his doors open. Please help me figure this out Audi lovers!!!!