According to me, mingling with other religion is only right. But if it's about dating I would suggest christians to date christians and muslims to date muslims. That is of none of them has plans of converting. Obviously it's evident that it's all a waste of time and resources. I don't mean that dating a christian then break up could not be a waste of time, it could be but dating someone from your religion increases your religion bond. But if both of you speak differently in matter of religion then u won't experience any spiritual growth. Everyone is out there for a relationship that will have a future and one that will lead to marriage and happiness. Considering parents decisions which is very important in our future lives, I am very sure no parents would support a lady who has been brought up in a christian background to just drop down her foundation and join a man in a very different background. My last suggestions every religion date their religion without interfering with others religion backgrounds, because sometimes love is blind.