Do you think they are nasty?

So my sister is in a situation with her boyfriend. They have been together for 4 years but only seen eachother once in 4 years due to distance and visa issues. Her "boyfriend" got with another girl and the girl found out about my sister. The boyfriend met up with this girl to tell her the situation and that he loved my sister. The girl then video called my sister while the boyfriend was explaining the situation and was laughing when my sister answered. She also start taking selfies of her and the boyfriend when the boyfriend was not looking and sending them to my sister. What do you think if this situation and the behaviour of the girl and boyfriend?

Do you think they are nasty?
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