He wrote 'busy this week, talk soon'. What does it mean?
“Busy this week” names a constraint, and “talk soon” leaves the next conversation open. In that wording, no day for talking is agreed. That is a limit of the plan, not proof of how much he wants you.
You can acknowledge the busy week without keeping an unspecified evening available. A concrete suggestion later would add something new to the exchange; repeating “soon” would still leave the scheduling question open.
The line you can send
Hope the week goes smoothly. Let me know a day that works, and we'll see if it works for both of us.
Yours will sound different
Bring the message you keep rereading. The first reads are free, and nothing is sent to him.
Ask about mine