What's the state of your relationship? Yours may have romance, love and a greatly understanding partner but there's a possibility the relationship may fail. What can you do to help your relationship?
Don't nitpick, as everyone has a tendency to do this. Stop looking at their peculiar habits and this will help you to enjoy their company more. You're not your partners parent. Talk about these things.
Try discussing any issues which you may face with your partner. Solve the problem instead of dumping it, leaving then coming back to argue even further. The problem is still there, earlier or later, but later it may get worse so nip it in the bud before it escalates
People who select the wrong partner find it difficult to settle in the relationship. Weigh all the advantages and disadvantages on who will be an ideal person in your life. Changing someone to your needs or idealism can be difficult and a strain on the feelings of the heart hen things start to sour because of poor choices.
To really make things work you must accept the flaws of your partner as no one is perfect. Before you both met you were different people leading different lives and acceptance of silly, crazy and sometimes irritating things the other one does is all part of the process of the work in the state of the relationship.
Bar Advice. Do not be jealous when meeting their ex or when a person in previous relationship is mentioned. Before you became a couple other people were in your lives...remember that.