Why is this nurse the only nurse that treats me like this?

I had a sarcoma cancer several months back and now I’ve just finished my 4th cycle of chemotherapy and whenever i finish I cycle I must take the immunity shot in the belly or thigh but I always choose the thigh so all the nurses that ever came in my room and put emla plaster before the shot she she just puts the emla and goes away for 15 minutes and then she comes to remove the plaster to give me the immunity shot but there’s 1 nurse that she rubs over the plaster with her own hand and laughs and once she also rubbed over my chest she said I’m just checking your port, then why no other nurse has been that nice to me? And the nice nurse is actually a grandma because yesterday was her grandson’s birthday and I’m 28 years old only so why is she acting this way around me?
Why is this nurse the only nurse that treats me like this?
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