There are many ways you can defeat these kinds of issues before they ever become a problem. It all comes down to good communication. Being open and honest with your significant other and drawing the lines where they need to be drawn. If this is not a conversation that you are able to have, there are bigger concerns you need to worry about. A lot of this boils down to trust.
If you think that you are going to be in a situation that might cause concerns or could potentially look bad, it is important that there is open and honest communication. If you have to ask, chances are good that it will become an issue. Head the problems off. Why not? A little communication can prevent a whole host of problems. Plus, if they have to ask, you are not doing your part to ensure that the relationship is strong and mutual.
I am not talking about surprises for birthdays, special events, or other things that are similar. I am talking about being around questionable people or putting yourself in a questionable situation that might cause distrust or resentment. Some examples might be communicating with or being around an ex-relationship partner, or going to an event without them that is not conducive to a good relationship. Does your current partner know what is going on? Is it something that might make them uncomfortable?
If you have to ask yourself these questions, you might as well assume yes because it is clearly something that hasn’t been discussed or agreed upon. Have a sit down conversation with your partner. Ask them what they are OK with and what makes them uncomfortable. Don’t hide things or mislead them. If you have to lie to or deceive them, you are better off asking why you are in that relationship in the first place. What is the point of being romantically involved with someone you have no intention of being open or honest with? Have those talks. It is better for everyone involved.