@John seJerman
Welcome to the expat.com forum, and many congratulations on your early retirement. Good luck with your move to lovely Spain!
The short answer to your question is: No, not usually. :-) Here's my longer effort...
3-5 months isn't long. You should note that you both (I think) have visa-free allowance of 90 in 180, so you can actually spend 3-5 months even as tourists (although in 2 or more stays). You don't need to be a legal resident to purchase or rent a property. And if you're a wealthy guy, you might want to think twice before settling on a relatively high-tax country as your new home base.
EU citizens have a very easy process to become legal residents, the "EU Citizen Registration". Typically, it requires proof of address (in Spain), proof of health insurance (in Spain), proof of funds. Then you do the "Family Reunification" step to get residence for your partner. As a bonus (you might be aware already), Spain has a very favourable (2 years) path to Spanish citizenship (and EU passport) for citizens of "Ibero-America" which includes Peru, of course.
At this point, after these two steps/processes, you are both legal residents. But not necessarily tax residents. And many folks (e.g. holiday home owners) have legal residence in Spain for many years without becoming tax residents. However, there are a few non-resident taxes that apply anyway (e.g. property tax, imputed rental tax) although they aren't usually very dramatic.
You might pay tax on your passive income in the country it was generated, but is that the country where you claim to be "tax resident"? Or are you trying to be a Perpetual Tourist (PT), without a home tax residence? It sounds that way if you've been travelling for several years only on tourist visa (i.e. in order to escape your previous - high tax - tax residence country). It's harder to avoid Spanish tax residence if you are a PT. And easier if you are, say, a German tax resident, and can prove this. If you're a PT currently, perhaps consider having legal AND tax residence in a low-tax EU country (e.g. Ireland, Bulgaria, Portugal with its D7 tax exemption) instead? Or having your legal and tax residence in the country where you generate your passive income?
Separately, you need to avoid becoming a tax resident of Spain. The main test is the "substantial presence" test, as 183 days or more makes you a tax resident. So travelling (being absent from Spain) for more than 6 months a year would be necessary, and your "3-5 months" in Spain would meet this time requirement.
HOWEVER, Spain has other tests, so you would need to check further. For example, your "centre of economic activity" (where most of your work / wealth is). If you have, say, a 5 million euros beach-front villa in Sitges, and a 100k apartment in Germany, you might get caught by this. Whereas, say, a 5 million $ stock portfolio in the USA and a 200k euros apartment in Alicante looks more plausible. Spain also has some automatic tax residence rules for YOU based on your spouse/family/children, so you need to check this one carefully. I think those are the main ones, but it might be worth a consultation with a Spanish tax attorney.
You might find it hard to get the Spanish passport for your partner, and avoid the tax net (as she has to live there most of the time to qualify for the passport, hence becoming a tax resident, hence making you a tax resident). If you forget the passport (might be difficult, if your partner knows about it, she probably wants it!), and both stay outside 6 months plus... and have a modest (or more modest) property compared to your official home base... and retain tax residence in another country... it might be OK. :-) But I'd suggest it's not a slam dunk.
