I have a girlfriend who I grew up with and every time I message her I get the I am busy or working now , can't talk now So hearing you say how you feel kind of hits me and thinks maybe she feels the same way .

I know you said you don't want to hurt him by being honest . But the truth is you are hurting him slowly because every time he reaches out to you your telling him your busy in other words I have no time for you . So you are hurting him even tho you may not think so .
That was why I said just be honest with him and not lead him to think there is something when there is nothing .

I wish my friend would just say I don't want to chat with you instead of giving me
excuses .