It's a decision you have to make depending on your finances.
If you can work for 3 months on the startup without feeling any financial burden I'd go with that but if these 10 hours of work a week translate into a good chunk of money it may be worthwhile to do it.
A few questions to ask yourself:
1. Could the 3 months potentially turn into more?
2. Can you set the hours you will be working to accrue the 10 hours or will the client be calling you whenever they have issues? The first scenario is more preferable.
3. If you do the 10 hour option you can try to do it the same day as your partner so then you have more time together.
If you can work for 3 months on the startup without feeling any financial burden I'd go with that but if these 10 hours of work a week translate into a good chunk of money it may be worthwhile to do it.
A few questions to ask yourself:
1. Could the 3 months potentially turn into more?
2. Can you set the hours you will be working to accrue the 10 hours or will the client be calling you whenever they have issues? The first scenario is more preferable.
3. If you do the 10 hour option you can try to do it the same day as your partner so then you have more time together.
Just my thoughts..