There are a few things that we over look or don't take note or ignore in our various relationships which can terminate your relationship. See The Little Things That Leads To Break-up In Relationships.
1. LOVING THE PERSON TOO MUCH/CHOKING YOUR PARTNER WITH LOVE: No matter how in-love you both might be, the moment one is choking the other with too much love, it fizzles out the love of the other partner leading his/her love to depreciate. Try to always make it balance or else you just might scare your partner away.
2. DESPERATION: When you show signs of desperation in your relationship, like trying to trap the person to yourself through pregnancy or marriage, it scares the hell out of most people, especially if your partner is not ready to be hooked up or where the relationship is still at it's early stage. Don't talk about marriage except if you are both desperate about it.
3. IMMATURITY: No girl wants a kid as a boyfriend or someone who talks and does things like a kid! No no no no... she will definitely dump you! (vice versa)
4. MODE OF DRESSING: If your mode of dressing is really horrible, please do something about it fast! No girl wants her man to look like a mad man. Dress like a gentleman. (vice versa)
5. HYGIENE: Long/Dirty finger nails and toes also leads to break-ups in relationships. Bad breaths, body odour also terminates a relationship.
SOURCE: Nigerian's number one relationship blog LUV-KINGS