Should my boyfriend be helping his 8 year old daughter bathe?

My boyfriend and I have two daughters (each from previous relationships). His daughter (she’s eight, turning 9) lives with her mom and visits us weekly. My daughter loves with us and visits her dad weekly as well. When bathing my daughter (she’s 6), her dad and I give her privacy in the bathroom as well as changing in and out of her clothes. The only time we’ll come in is when she needs help with shampooing her hair. When my boyfriend bathes his daughter, she tends to ask him for help a lot when changing & bathing. At home, she’s totally capable of doing that herself just fine, but when she’s with us, it’s different. I’ve mentioned to him that she’s at an age now where she should have more privacy when it comes to baths here; she doesn’t want to do it alone. I don’t want to overstep because I’m not her bio mother, and I would like some advice or tips on how to go about the situation or if I should just leave it at that.

I don’t see an issue, he is her father. I help my kids whenever they ask

Every child is different. It may be extremely comforting for her or it’s just another way to maximize her time with her Dad… relax