Should we be concerned?

My boyfriend has told me about a few incidents he’s asked me for advice on and honestly I don’t really know what to say. His 7 year old daughter asked to come into our bed in the morning and also if he could ‘tickle her bum’. He said no and ushered her to brush her teeth as it was time to get ready anyway. Then tonight whilst she was reading her bedtime story to him she stopped and asked if he could smack her bottom before she goes to sleep. He’s brushed it off and said stop being silly finish reading and she got on all fours and said ‘come on daddy smack my bottom’. She has also previously walked out of the shower naked to do the splits in front of her dad and asked him if he likes it. I took her shopping last weekend and she kept picking out clothes that were inappropriate for a little girl. I am a boy mum myself and haven’t experienced this so I don’t know if this is ‘normal’ behaviour but I certainly wasn’t like this with my own dad. We have little insight as to her life with her mum (she was sadly sectioned) so we don’t really know where she would have gotten these ideas from. She does not have free rein access to the internet with us, so we can rule that out. I guess what we want to know is if this is typical behaviour for a 7 year old that she will grow out of or should we be concerned that something awful has happened to her in the past? Any ideas on how to handle this please? Thank you.