score:7
Here is what the VWP says:
The Visa Waiver Program (VWP) enables most citizens or nationals of participating countries to travel to the United States for tourism or business for stays of 90 days or less without obtaining a visa. Travelers must have a valid Electronic System for Travel Authorization (ESTA) approval prior to travel and meet all requirements explained below. If you prefer to have a visa in your passport, you may still apply for a visitor (B) visa.
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You must have a passport that is valid for at least 6 months after your planned departure from the United States (unless exempted by country-specific agreements). For families, each member of your family, including infants and children, must have his/her own passport.
In addition, you must have an e-passport to use the VWP. An e-passport is an enhanced secure passport with an embedded electronic chip. The chip can be scanned to match the identity of the traveler to the passport. E-Passports must be in compliance with standards set by the International Civil Aviation Organization (ICAO). You can readily identify an e-passport, by a symbol on the cover. See the example below. More information about e-passports is available on the DHS website.
It, very unfortunately, does not say, anywhere, how many times maximum you can use the VWP, nor does it say how much (or little) time must lapse before you are allowed a second trip. Many people say "as long as the CBP officer is not inclined to believe you are attempting to live in the US", but there is nothing explaining what that means in real, objective terms.
Coming from an EU country, assuming COVID-19 restrictions are lifted, and as long as you can give some sort of specifics to your trips (I came in the summer to visit Montana for vacation, and now I'm coming for Christmas in New York. First trip was for 40 days and here is my ticketing info from that trip, and this trip is for a week, and here is my return ticket.) you'd have absolutely no issues, if you are even questioned, which (again unfortunately) depends upon your attitude, dress and general appearance (overall, your profile).
Before the down-votes happen from my last words, I finally point out that, in the US:
Customs and Border Protection (CBP) and the Transportation Security Administration (TSA) have exemptions to use racial profiling in "screening and inspection for border and transportation security" and "U.S. Border Patrol interdiction activities in the vicinity of the border and ICE Homeland Security Investigation (HSI) interdiction activities at ports of entry."