I've been with my boyfriend for 17yrs. Can he up and kick me out? He asked my sister for a relationship. So I spent the night with a friend. Now he's giving me 4 days to get out. Can he do this?

Local laws apply so please give us an idea where you are. Or Google rights of long term partners, and evicting long term partners and add your zip code, or state. It would seem though you may have many options living with someone so long.

https://www.nolo.com/legal-encyclope...apter10-1.html

https://family.findlaw.com/living-to...d-couples.html

https://www.citizensadvice.org.uk/fa...l-differences/

As noted, it will depend on where you live and if your name is on lease or house and so on.

But if the home is his, or he is the person renting, yes he can ask you to leave. The amount of time you have will differ.

My question why would you even want to stay, and risk losing all of your things, sounds like you would want to and should get out fast

As others noted, if the house is his (i.e. you don't have any ownership in the property or don't pay rent to the landlord), you are considered a day-to-day tenant, and so legally have some period of time to vacate after he gives you written notice to move out. This may be ten days, or perhaps 30 days, depending on the jurisdiction. It's understandable that it may take more than 4 days for you to find other living arrangements - that's why the law typically provides a longer period to vacate. But you need to decide whether to stretch this out to whatever time frame the law allows, or as suggested make plans to vacate ASAP.

I agree with the earlier post, you would need to supply State and County as jurisdictions are all different.