Here are a few tips for handling this tricky situation.
If you think you could eventually fall in love with them, focus on the potential.
Individuals in a relationship aren't guaranteed to experience falling in love at the same pace. If your partner has reached a place where they feel comfortable expressing their love but you still need more time, you should start by acknowledging how much you currently care for them.
"Tell them the depth of your feelings, in detail," relationship expert Susan Winter told Bustle. "Include the ways in which they make you happy and add value to your life."
By focusing on all the positive feelings you have toward the person, you're cushioning the blow they're undoubtedly feeling at not hearing you return the sentiment.
"If you can't yet say 'I love you,' then it's best to describe the growing emotional connection you're feeling your mate. This provides security, as it shows you're both moving in the same directions," Winter told Bustle.
If words don't seem like enough, a token of physical affection may help to show you're still invested in the relationship even if you're not ready to declare your love.
"If the 'I love you' is wanted, just not yet reciprocated, then I suggest a physical response of appreciation," relationship expert Kim Olver told Her Campus.
If you don't think you'll ever love them, it might be time to discuss the relationship.
If you know that you aren't likely to ever feel the same way as your partner, it might be best to be honest.
"Telling someone you don't love them is likely a starting point to thoughts of whether or not you even want to continue the relationship," relationship therapist Aimee Hartstein told Bustle.
This might be a chance to have an honest conversation about the future of the relationship.
If you don't love someone anymore, it could be time to end the relationship.
If you find yourself on the receiving end of love without feeling any in return, that could be a sign your relationship is in a difficult place.
"When desire has left, it's next to impossible to coax is to come back," family therapist Vikki Stark told Psychology Today. "And that can be a sadness for the person who no longer feels the want, as well."
It's possible to love someone while feeling like you're not actually in love with them anymore. When that happens, it could be worth considering whether the relationship is salvageable or if it would be healthier to end things.
If they react to not hearing "I love you" with anger, it may be a red flag.
Professing feelings of love would make anyone feel vulnerable or disappointed, so you should expect your partner to be dealing with certain level of sadness or even embarrassment.
However, if they seem genuinely angry that you don't reciprocate their feelings, it could be a red flag.
"If your partner is feeling that you have to say it back or else the relationship is over, or I have to go find someone else, or they don't really care about me, that's immaturity," dating coach Kate Stewart told Refinery29. "There has to be space for people to develop those feelings on their own."
Not feeling the same way at the same time shouldn't be used as a breakup threat or ultimatum for finding someone else. Above all, you should never feel pressured to return an "I love you" if that's not how you're actually feeling.