Does my partner have to be on the tenancy agreement?
If the tenancy agreement is in your name, you have the right to remain in your home. You are also responsible for making sure the rent is paid and that the terms of the tenancy agreement are complied with. If you are a joint tenant with your partner, you both have the right to carry on living in the property.
Can my partner throw me out of his house?
No! Legally, it's her home, too—even if it's only his name on the mortgage, deed, or lease. It doesn't matter whether you rent or own, your spouse can't just kick you out of the marital residence. Of course, that doesn't mean that, sometimes, for whatever reason, it's not better to just go ahead and leave.
Is it okay for my boyfriend to follow his ex?
Exes are an important part of many people's histories, and it's OK to want to keep in contact with them — as long as it's at a safe distance. If your partner is following their ex without engaging in much of their content, this probably isn't anything that should concern you.