<human>: Can you provide a brief rundown of the text in within 3 sentences?

Me and T (24 F) have been best friends for almost 20 years, we have been though a hell of a lot together and have always had each others backs.

T has been with her SO for over 4 years, they got together some time after T's mothers passing, a time witch he was helping her through and became close.

The SO [23 M] is a shy, calm dude, T is very bubbly, loud and kinky. She is very much in love with her SO, she never wants to be without him and is terrified of hurting him.

The first affair was with a female co worker of T, she came clean with her SO about her intentions with the girl and her SO aloud it to go a head. They are now seeing each other occasionally, and her SO is hopping for an invite to the bedroom.

The second affair worries me a great deal, with another co worker [M/20 something/Engaged]. She told me this romance is complete lust, she likes the way he makes her feel sexy and wanted. The biggest part I believe is the change of sex style, her SO being very vanilla, her Lover [M] is a sex addict with a rough streak (witch she confesses she loves).

I am deeply worried for T, she is a wonderful girl and this is very out of character. I don't want to push her away by telling her what to do, but surly this path she is choosing is going to end badly. Looking for advice.
<bot>: My best friend [F] has started having two affairs [M&F], I'm worried for her, any advice?