The appropriate response to receiving the KM emoji ? in a text message depends on the context and the relationship with the person sending it. For instance, if the message came from my wife and we were having a regular conversation, and she added "Ok baby, I'll talk to you later, I love you ?," I would respond with a similar message.
However, if we were joking around and she added the KM emoji ? with the peach emoji, I would respond with the KM emoji ? and the eggplant emoji.
If a male friend sent me the KM emoji ?, I would interpret it as a flirtatious message and respond with the "O-face" emoji and the eggplant emoji.
On the other hand, if a female friend sent me the KM emoji, I would assume it was a friendly gesture and not flirtatious. I would respond with three red hearts and leave it at that. If I felt that they were flirting with me, I would kindly remind them that I am happily married and that my spouse and I have agreed to cut out anyone who tries to interfere in our relationship.
It's important to note that the KM emoji ? can have multiple meanings, not all of which are sexual or flirtatious, and the appropriate response will depend on the specific context and the relationship with the person sending the message.