If salman has said so, then sid is mature enough to catch the hint. Sid knows already Sana does all to make paras feel jealous or he believes so.
But if Sallu said she used to like paras and to get to gim she came to you but in that process she got attached to you, then Sid should understand and believe it. That she is genuinely into him if she is saying it that she loves him and has feeling with him and is possessive for him, then she us not lying. He is sensible enough to see this. If still he doesnt get it then he dsnt want to get it.